Acetone resin compositions and process of making same



, insoluble resin which when Patented Dec. 12, 1944 ACETONE aEsIN'coMrosrrroNs AND MAKING SAME PROCESS OF Frederick A. Bessel, Upper Montclair, and John 1., assignors n of New Jersey B. Rust, Verona, N.

Company, a corporatio to Ellis-Foster No Drawing. Application January 9, 1941, Serial No. 373,798

7 Claims.

This invention relates to a water-soluble acetone-formaldehyde condensation product and particularly to heat-hardenable compositions containing a water-soluble acetone-formaldehyde condensation product and water-soluble formaldehvde-condensable nitrogenous bodies.

As hitherto practised, when 1 molecular equivalent of acetone is combined with 6 molecular equivalents of formaldehyde under alkaline conditions, a more or less light-colored resinous material is obtained which is insoluble in water but, depending upon the degree of reaction and possibly upon the amount of strong alkali catalyst, it is either light-yellow and insoluble in all organic solvents (Plauson, German Patent. 351,349) or is light-colored and soluble in alcohol and the like (Ellis, U. S. Patent 1,683,535). The alcohol-soluble product when heated (and particularly when heated with caustic alkali) is converted to an insoluble heatresistant body- We have found that acetone and formaldehyde in the proportions of 1 mole acetone to 6 moles formaldehyde can be condensed to yield a hard, water-soluble, alcoholheated alone or with added alkali remains water-soluble and fusible. Although permanent water-solubility is often undesirable, we have found that if the resin is mixed with water-soluble nitrogenous bodies of a type hereinafter explained, a composition is obtained which when heated becomes hardened, that is, it becomes insoluble and infusible.

The alcohol-soluble (water-insoluble) condensation product of 1 mole of acetone and 6 moles of formaldehyde has been incorporated with urea-formaldehyde solutions (Ellis, U. S. Patent 2,029,525). Also, various waterand alcoholsoluble acid-condensation products of acetone with low molecular amounts of formaldehyde (from .2 to 2.6 moles of formaldehyde per mole of acetone) have been incorporated with certain synthetic resins, proteins, etc. (Novotny and Vogelsang, U. S. Patent 2,191,802). Furthermore, it may be noted that water-soluble, potentially hardenable condensation products of acetone with relatively low molecular propor-' tions of formaldehyde have been applied as a size to fabrics and baked thereon to render them shrink resistant (Zwicky and Brunner, U. S. Patent 2,159,875).

It is an object of this invention to prepare compositions containing va permanently watersoluble and fusible acetone resin and admixed nitrogenous bodies, which compositions are hardenable undenheat. It is also an object to prepare aqueous compositions or solutions containing the water-soluble acetone-formaldehyde condensation product and a water-soluble nitrogenous body for use as coating compositions, adhesives, cements, paper and textile sizes,

- and the like.

binders for molding compositions to produce molded articles including pressed cork products. A particular object is to prepare aqueous compositions which can be applied to textile materials to produce a permanent finish thereon and improve them in such qualities as draping. Other objects will appear hereinafter.

The acetone-formaldehyde product which we use is obtained by refluxing 1 molecular equivalent of acetone and 6 molecular equivalents of formaldehyde in the presence of a substantial amount of a. very mild alkaline condensing agent such as disodium phosphate or borax, the condensing agent being a compound whose aqueous solution shows a pH of around 9.5. The reaction mixture remains homogeneous throughout the heating and an is that the reaction is easily controlled. After refluxing for some hours, water is removed (pref erably under reduced pressure in order togpre serve the water-white color) and the final product is obtained as a hard transparent resin soluble in water and which does not harden when heated alone or with is not soluble in ethyl alcohol in a practical sense. For example, a mixture of equal parts resin and alcohol on standin shows a two-phase system.

The lower phase is viscous liquid (resin sof-' tened by absorption of alcohol). The upper phase is alcohol. When shaken a turbid emulsion-like liquid is obtained. The resin as prepared still contains the alkaline condensing agent and. therefore, subsequent hardening in the presence of the nitrogenous body occurs under mild alkaline conditions.

Acetone is the preferred ketone from which to make the resin although higher ketones such as methyl ethyl ketone can be substituted, at least partially, for acetone. Aqueous formaldehyde is an advantageous. form of the aldehyde since aqueous compositions are concerned, but polymeric formaldehyde can also be used. The resinwill hereinafter be designated watersoluble acetone resin.

The following is a preferred formula for making the resin:

A mixture of 145 parts of acetone, 1200 parts of 37.5% aqueous formaldehyde and 60 parts of borax were refluxed together for 6 hours, after which an additional 60 parts of borax was added and refluxing was continued for 6 hours. The product was then dehydrated on a water bath *underiieduced pressure to give a water-white,

hard, brittle, transparent resin, soluble in water, insoluble in alcohol and which. when heated at C. for 2 hours or more is still water-soluble. Heating the resin at 140 C. in the presence of caustic soda causes no darkening and also does not produce water-insolubility.

forconvenience Although it is advantageous advantage of the procedure a strong alkali. The resin tion mixture or partially to dehydrate the same. Nitrogenous bodies with which the watersoluble acetone resin may be mixed to yield heathardenable compositions include proteins such as gelatin, casein, glue; amides, such as urea and thiourea; melamine, dicyandlamide; and watersoluble intermediate or partial condensation products of urea, thiourea, melamine or dicyandiamide with formaldehyde, thelatter group ineluding these compounds reacted with insufficient formaldehyde to yield a condensation product which is capable in itself of hardening when heated. Mixtures of two or more compatible nitrogenous substances may be used if desired. These bodies are all condensable with formaldehyde to a hardened, substantially water-insensL tive condition; also they are all water-soluble. It will be noted that the present invention involves two water-soluble substances either of which when heated alone does not harden but which when mixed and heated'produce a mutual effect whereby a water-insoluble composite results. The water-soluble nitrogenous body is insolubilized (that is, fixed) by the acetone resin and vice versa. Although water-solubility is a requisite characteristic of the formaldehyde hardenable nitrogenous bodies, in certain cases (for example, with melamine where water-solubility is less pronounced) it is desirable to add some alcohol to improve stability of the solution on storage. Also, the addition of of alcohol improves the fiow of the aqueous compositions when films or coatings are desired.

Curing or fixing appears to be more rapid when it occurs when the composition is in contact with cellulosic material as when a composition is applied to cloth and subjected to elevated temperature. For example, a mixture of gelatin and acetone resin applied to cotton cloth from aqueous solution and the cloth dried and subjected to a temperature of 140 C. for minutes yields a laundry-resistant filled material. A similar composition applied as a film to glass and baked for the same time and at'the same temperature is still baking in order to be fixed. Curing temperature is above 100 C. and any temperature may be used between this point and about 170 C., the temperature in any case being below the thermal decomposition point. The higher the tempera ture the shorter the time required for fixation.

As mentioned previously, curing of the composition occurs under mildly alkaline conditions. This is particularly advantageous when textile treatment is concerned. It is known to treat fabrics with a solution of urea-formaldehyde condensation product and cure the resin on the fabric by heating. However, ditions is necessary and this is liable to tender the cloth, particularly if fastcuring is required.

Although certain substances such as urea and thiourea compositions, when used according to the present invention result in yellowing whichprecludes their use on white (but not darker colored) goods, it is possible (for example, with many proteins and melamine compositions) to obtain colorless cured materials. Equal parts of acetone resin and nitrogenous body are often satisfactory proportions although the amounts may be varied within certain limits. For example,the proportions may vary between 1 part of resin to from to 2 parts of the added nitrogenous body. It will be apparent that the water-soluble and requires longer curing under acid con-- amount of acetone resin necessary to use with the nitrogenous body in order'to produce hardening is substantial, and is quite different than catalytic amounts. Hence, the term hardening agent as used in the claims denotes a reactant which adds materially to the composition weight.

The following examples are given to illustrate the foregoing. All parts are by weight.

Example 1.A mixture containing 1 molecular proportion of melamineand 4 molecular proportions of formaldehyde as neutralized 37.5% aqueous aldehyde washeated under reflux until the melamine was dissolved and then heating was continued for 10 minutes. 355 parts of watersoluble acetone resin was mixed with 635 parts of the cooled syrup, which resulted in a clear liquid of high viscosity. The aqueous composition was applied to a glass panel to form a film. When the film was baked for 5 minutes at 140 C. it was insoluble in water. A similar film was insoluble in water when baked 3 minutes at 160 C.

Example 2-635 parts of the melamine-formaldehyde solution described in Example I was added to 360 parts of water-soluble acetone resin, 732 parts of alcohol and 5350 parts of water to form a water-white solution containing approximately 10% solids. Cotton cloth was soaked in this solution, wrung on rubber rolls, air-dried and then baked at 140 C. for 15 minutes. After baking a marked stiffening of the cloth was noted which persisted after the cloth had been washed for 1 hour in a 1% soap solution at C. Also no loss of body in the cloth was noted after soaking for 2 hours in carbon tetra- Minutes Soluble in water 5 Partially soluble in water 10 Insoluble in water 15 Example 3.A melamine-formaldehyde reaction product in the form of a clear syrupy liquid was obtained by refluxing for about 10 minutes a mixture of 63 parts of melamine and 160 parts of neutral 37.5% aqueous formaldehyde. 20 parts of this syrup and 11.2 parts of water-soluble acetone resin were mixed to form a clear solution which was diluted with water to 100 parts. Cotton cloth was immersed in the solution for about 3 minutes, wrung between rollers and baked at 140 C. for 15 minutes. A definite stiffening effect on the cloth was obtained, which stiffening was retained after the treated cloth was washedsin 1% soap solution at 100 C. for an hour.

Example 4.5 parts of melamine was dissolved at 100 C. in '70 parts of an aqueous solution containing 10 parts of water-soluble acetoneresin. 15 parts of alcohol was then introduced. Cotton cloth samples were immersed in this solution. wrung out and placed in an oven at C. for lengths of time varying from hour to 2% hours. A stiffening of the cloth resulted. All samples were washed in 1% soap solution at 100 C. for an hour, followed by rinsing and drying. Each sample retained a stiffened effect after the washing treatment.

Erample 5.A solution containing 14.3% was made consisting of solids 1% soap flake solution or after 2,304,000 a 3 Parts That we claim is:

A composition comprising a water-soluble $22; mluble acetone resin icrmaldehydemardenable nitrogenous body seg'g gaa n6 lected from the group consisting oi melamine and Melamine 12 partial condensation products of melamine with Five samples of cotton. cloth were immersed in this solution, wrung on rubber rollers, dried at and baked at 140 C. for 5, 10, 15,20 and 25 minutes, respectively. This resulted in a stiffening eflect. All the samples were then given a soak of 1 hour in 1% aqueous soap solution at 05-100" 0., then rinsed and dried by ironing. The 5-minute sample seemed to have lost all its hodying by the washing treatment. The -minute sample retained some stiffness and the other samples were found to be substantially unaiiected by the washing.

Example d-Cotton cloth was soaked for 0 minutes in a solution consisting of 10 parts water-soluble acetone resin, 1 part gelatin and 100 parts water. The sample was wrung. dried at room temperature and then baked for minutes at 140 C. A stiffening effect was obtained which persisted after heating for 1 hour ,in a soaking for 2 Films of the solution also were obtained on glass and baked at 140. Afer minutes at this temperature they were still soluble in water. The water-insolubility obtained on the'treated cloth indicates the increased curing rate of the composition when in contact with cellulosic material.

Example 7.-l0 parts of'alkali ease and 10 parts of water-soluble acetone resin were dissolved in parts of water. Cloth treated with this solution and baked at C. for 30 minutes received a stiflcning which was permanent to washing.

Example 8.-2 parts of animal glue and 2 parts of water-soluble acetone resin were dissolved in 06 parts of water. Cloth impregnated with this solution and baked at 100 C. for 30 minutes received a still finish which was retained after washing with hot soapsuds for an hour.

Example 9.--A series of compositions was made soluble acet ne resin. oil at 100' C. and the residues were heated at C. for 15 minutes,- after which they were examined for solubility in water.

A. 0.5 part Final product lightweij lowandinsolubleinwatel'. B. 1.0 port melamine. Final product light yellownnd hlolnble in water. c. 2.0 parts melamine. Final p not light yellow and insoluble in water p. 3.0 parts melamine. Final product right yel-' age t.

formaldehyde and, as a hardener therefor under the influence of heat, a water-soluble acetone resin consisting oi the reaction productoi 1 mole of acetone with about t moles oi iormaldehyde in the presence oi borax as condensing agent.

' said resin containing the condensing agent.

2. A composition comprising melamine and, as a hardening agent therefor under the influence of heat, a water-soluble acetone resin consisting of the reaction product at i mole oi acetone with about 6 moles oi formaldehyde in the presence oi borax as condensing agent, said resin containing the condensing agent.

3. A composition comprising a water-soluble partial condensation product of melamine with formaldehyde and, ass hardening agent therefor under the influence of heat, a water-soluble ace= tone resin consisting of the reaction product of 1 mole of acetone with about 6 moles of formaldehyde in the presence of borax as condensing agent, said resin containing the condensing agent.

4. An aqueous composition suitable for application to textile fabrics to produce a permanent finish thereon under those conditions wherein a. 30 fabric is impregnated and baked, comprising a water-soluble formaldehyde-hardenable nitrogenous hody selected from the group consisting of melamine and partial condensation products of melamine with formaldehyde and, as a harden- 35 mg agent therefor under the influence of heat,

a. water-soluble acetone resin consisting of the reaction product of 1 mole of acetone with 6 moles of formaldehyde in the presence of borax as a weakly alkaline condensing agent, said resin 40 containing the condensing agent.

5. The process of making a composition which is capable of becoming insoluble and infusible under heat, which comprises incorporating a water-soluble formaldehyde-hardenabie nitrogenous body selected from the group consisting of melamine and partial condensation products of melamine with formaldehyde, with a water-soluble acetone resin which consists of the reaction product of 1 mole of acetone and about 6 moles of formaldehyde in the presence of borax as a condensing agent, said resin containing the condensing agent.

amine, with a water-soluble acetone resin which consists of the reaction product of 1 mole of ace- 7 tone and 6 moles of formaldehyde in the presence of borax as a condensing agent, said resin containing the condensing agent.

'l. The process of making a composition which I is capable of becoming insoluble and infu'sible under heat, which comprises incorporating a water-somble partial condensation product of melamine with formaldehyde, with a water-soluble acetone resin which consists of the reaction product 01' 1 mole of acetone and 6 moles of formaldehyde in the presence of borax as a condensing agent, said resin containing the condensin FREDERICK A. BESSE JOHN RUST. 

